This invention relates to the field of truck tailgate structures, specifically to structures for locking truck tailgates into various operative positions.
U.S. Pat. No. 4,029,355 to Wilhelmsen discloses a locking mechanism for a tailgate (see FIGS. 3 and 4) in which the mechanism locks by being latched through extending pins into a provided elongate notches on an extension on either side of the truck bed body. Note that nothing secures this gate in a downward position other than the weight of the tailgate, and only the contact of the base of the tailgate (unnumbered but near numbered item 25, FIG. 2) supports the tailgate horizontally in a downward position.
U.S. Pat. No. 1,883,473 to Barrett discloses an adjustable tailgate mechanism in which a locking or latching hook (27) pivoted on an eccentric arm (28) is activated through rotation of a rock shaft (29) activated by lever (30) to release and then latch the tailgate in a downward or an upward position.
U.S. Pat. No. 2,891,816 to Meats discloses a tailgate fastening mechanism in which a pivoting lock hook is fastened to an axis which is then turned by a cam and an elongate member to release and latch a dump gate or a tail board on a tipping vehicle. Again, this mechanism shows no ability to lock the board in one of two positions.
U.S. Pat. No. 2,258,447 to Fairbank discloses a form of shielded hinge for a tailgate on a dump body but does not otherwise disclose a locking mechanism.
U.S. Pat. No. 2,689,764 to Park, in disclosing a removable lift gate assembly for installation on varying truck bodies discloses the use of a lip (9) for supporting the tailgate (7) in a downward position when opened.
U.S. Pat. No. 2,151,335 to Rush discloses a spring balancing mechanism for supporting the weight of the tailgate but does not show a mechanism for supporting the tailgate against any load in a horizontal position.
U.S. Pat. No. 3,574,391 to Deboze discloses a hinge construction for a vehicle tailgate which is designed to provide an unobstructed surface when the tailgate is fully opened.
U.S. Pat. No. 2,145,926 to Gooder discloses an alternative form of hinge, specifically mentioned as being for the side gate or drop side which permits the drop sides to be laterally slid as well as being opened and closed.
U.S. Pat. No. 2,821,942 to Goodwin, in disclosing an end door for a drop in gondola car discloses a mechanism for limiting the travel of a torsion spring retainer attached to a drop gate in which a bar, item 35, or block is pivoted about a rivet and has four sides providing four separate setting distances for latching an arm (30) for controlling the position of the arm in opening and lowering the drop in.
The patents taken together or individually do not disclose the mechanism of my invention in that they do not disclose a hinged bar, offset from the point of pivot of a tailgate which may be swung into two positions, a first position latching the tailgate in an upward position and a second position latching the tailgate downward or over and against supporting fingers against upward motion. Although several patents show tailgates resting on extended fingers, none show a weighed latch-down over the fingers, and none show a single mechanism which both latched up and down.